Process of heat treating



Aug. 20, 1935. o. H; HANSEN PROCESS OF HEAT TREATING Filed May 2, 19:51 2 Sheets-Sheet 1 nwsmog;

A TTORNEY Aug 2Q, 19350 7 c. HIHANSEN 32,913,533

PnoblJss OF HEAT TREATING Filed May 2, 1931 2 Sheets-Sheet 2 L::: /9 la I nwzmoza; (0. W.

A TTORNEY the same.

5 Patented Aug. 20, 1 935 UNlTED STATES PATENT OFFlC-E- 2,011,631- rnocnss or nm'r mna'rmc Oswald H. Hansen, Cedar-burg, Wis. Application May 2 1931, Serial No. 534,550

v 12 Claims. 7 The present invention relates generally to improvements in the art of preserving foods, and relates more specifically to an improved process of heat treating edible substances in order to sterilize and permanently preserve the same.

A general object of the invention is to provide an improved process ofquickly, effectively and automatically heat treating various classes of ediblelsubstances-orfoods, in order to prevent spoilage thereof and to permanently preserve Numerous methods of heat treating edible sub-' stances in order to preserve the same by destroying destructive micro-organisms in the product, have heretofore been proposed and utilized, but none of these prior'methods have proven satisfactory for the treatmentof certain classes of foods. In order to successfully and commercially sterilize certain classes of foods such as green peas, beans, whole grain corn, and the like, it is requisite .to heat treat the same quickly and effectively and without deteriorating the product, eithenbefore or after the commodity has been packed in its final containers.

As disclosed in Patent No. 1,563,971, it has heretofore been suggested-to sterilize food products after batches thereof are placed in the cans, by first producing a partial vacuum in each can and o bysubsequently injecting live steam and sealing the cans,

tents of the sealed containers. This prior process is, however, impracticable. for the-treatment of all foods because it is not feasible to'inject enough steam to insure complete sterilization, and'also because the steam-at high temperature may scorch or burn the commodity.

- containers.

. effectively applicable in the treatment of some As disclosed in Patent N 1,756,550, it has also been proposed to heat treat food'products, by

admitting to the voids of pro-heated solids or v granular material, a heated fluid containing sumcient heat units to eifectively sterilize the mlx ture which is subsequently packed in the final While this process is readily and food products, it cannot be applied without modiilcation, to the treatment of others. Some products are so delicate, that if they are subjected to heat suiiiciently high to produce complete sterilization within a desirably short period oftime, while subjected to low external pressure. the-granules will burst due to excessive internal 7 pressures created during heating thereof. In

' accordance with this prior process, it is also contemplated to maintain the final product imthereof maintained wit 1 commodity.

dition. it being intended to have the vacuum assist the steam in'permeating through the con- (01. os-s) mersed in the initial heating fluid, and this is'also Y7 frequently objectionable as it destroys the natural appearance and taste of the commodity.

As disclosed in Patent No. 1,857,450, it has,

, moreover, been proposed to obviate the danger of bursting of the granules when heat treated in accordance with the method set forth in Patent No. 1,756,550, by admitting the heating medium to the-vids of the solids or granular materials, while the latter are maintained under sufliciently high external pressure to prevent such destructive bursting. This treatment of the substance may be efiectedeither before or after the same has been placedin containers, and insures effective and uniform sterilization of the product.

The present invention contemplates provision of new and useful improvements in the latter of the above-described processes, whereby certain classes of food products may be more effectively treated and the natur appearance and taste out dry packing of the Another specific object of the invention is to provide an improved process of quickly and etfectlvely reducing the temperature of food products after sterilization thereofin a heating me-. 'dium which has subsequently-been removed so as to leave the products in highly heated con- While the improved processor heat;,treating isespecially applicable for efl'ectivel'processing' of only certain classesofmaterial, the inventionbesides saving labor and eliminating losses, enables' embodiment in aslngle machine unit of practically all of the numerous machi nes now utilized in a canning factory,thereby reducing the canning plant to its simplest form. a

, the present application is a continuation in part.

specification, in which like reference characters designate the same or similar partsin} the various views. A I

Fig. 1 is a central vertical section through a combined granular material measuring, feeding and sterilizing device for delivering pre-measured "a .l pockets l9 always being disposed in vertical alinebatches of granular material mixed with liquid, to successive cans of a series;

Fig. 2 is a transverse section through the device of Fig. 1, taken along the line II -H of Fig. 1;

Fig. 3 is a fragmentary vertical section through the device, taken along the line III-III of Fig. 2;

Fig. 4 is a fragmentary vertical section through the device, taken along the line IV-IV of Fig. 2; and

Fig. 5 is a fragmentary vertical section'through the device, taken along the line V-V of Fig. 2.,

In accordance with-the present improvement,

solid or granular material is sterilized either in a bulk or in batches, by first immersing the same under relatively high temperature and pressure in a heated liquid containing suiiicient heat units to effectively sterilize the solids or granules. The

- heating liquid is applied at a temperature sumciently high to completely sterilize the solid or granular material and above the normal boiling point of the liquid, and when immersion is being eifected, the substances are preferably maintained under sufficient pressure to prevent actual boilin of the liquid. After suflicient heat has been applied to and absorbed by the solid material or granules, the liquid is removed and the heated solids are subsequently mixed with other previously sterilized liquid to thereby initially cool the .cans, with the aidof cap "machinery associated with ,sterilizing apparatusin a manner similar to that v{disclosed in said Patent No. 1,857,450. The herr'netically sealed mixture is then permitted to provement is more treatment of food commodities in bulk. It is desolids, The mixture of liquid and solids is subsequently packed while maintained under relatively high pressure, in receptacles such as tin applying and closing the measuring and .finally cool; thus completing the processing operation. i

While the improved process will be described herein as specifically applied to the treatment of successive batches of granular material, the imgenerally applicable to the sirable, in all cases, to gradually relieve the pressure on the granular material so as to prevent destruction of the granules.

Referring to the drawings, the combined measuring, feeding and sterilizing device shown there- 16, the top of the rotor snugly engaging the lower .portion of the closure l2. The rotor I4 is freely vertically removable from the chamber 13 upon I removal of the top closure 12, and is rotatable directly by means of a main vertical drive shaft l1 having a driving head I3 at its upper end coacting with a socket formed in the lower central portion 1 of the-rotor I4.

. --An annular series of granular measuring pockets 19 of variable volume, are formed in relatively ad- ,justable upper and lower members 20, 2 I, the lower of which rests directly upon and is rotatable relatively to the fixed closure 12, these measurin ment with the corresponding mixing and steriliz- V ,ing pockets l5, located therebelow.

A The upper member 20 of the set which forms the pockets I9, is rotatably supported upon a nonl2 coacting therewith to form a sealed rotary adjusting ring 22, and the lower member 2! has an integral sleeve 23 which is detachably but drivingly connected to the upper end of a sleeve 24 formed integral with the rotor M. A non-rotary but vertically adjustable top plate 25 to which the adjusting ring 22 is attached. coacts with the upper member 20 and provides a support for the granular material supply hopper 25. The

top plate 25, ring 22 andupper member 20.are

' simultaneously vertically adjustable relative to the lower member 2|, by means of a hand wheel 21 and screw 28.

The hub of the hand wheel 21 rests directly upon the 'upper extension of thetop plate 25, and the screw 28 which is keyed to the hand wheel hub, has a collar 29 reacting against alower surface of the plate-extension, and also has a threaded lower end coacting with a central non-rotary element 3ll.- The element 30 is fixed against vertical displacement relative to the rotor l4, by means of 'a screwplug 3| at the lower end of this element, and a shoulder 32 at the upper end thereof coacts with the upper end of the sleeve 24 which is formed integral with the rotor l4. A pin 33 rigidly attached to the element 30, passes through 'a. hole in the upper extension of theplate25, thus preventing relative rotation of the element and plate 25, while permitting free vertical movement of the plate 25 and of the elements carried thereby in order to vary the volumes of the pockets l9. The plate 25 and the element 30,

I may be anchored against rotation in any suitable manner in order to prevent lateral] displace.- ment of the hopper 26.

The chamber 13 and pockets l5 may be supplied with steam under pressure and at any desired temperature, by means of one or more steam inlet pipes 34 havingcontrol valves therein, these pipes communicating with the chamber I3 remote from the opening 35 in the closure plate 12 through which the measured batches of granular material are adapted to be delivered by gravity into the corresponding pockets l5' located therebeneath. The bearing plate It is provided with a discharge opening 36 which is adapted to deliver the successive sterilized batches of material from the pockets I5 to the chamber within the lower casing I I. The bearing plate l6 also has a succession of openings or slots 31, 38,39 thereinas shown in Figs. 1, 2 and 4. The slots 31 communicate directly with a heated liquid supply-pipe for delivering the sterilizing liq uid upwardly through the batches of granular material in the successive pockets 15. The slots 38 communicate directly with a drain pipe 4| for automatically removing the heating liquid from the granular material in the pockets 15, after the granules have absorbed sufficient heat for sterilization purposes. The slots 39 communicate directly with a sterile liquid supply pipe 42 for delivering relatively cool pre-sterilized liquid to the successive batches of granular material prior to delivery thereof to the cans.

Located within the lower casing H, is a series of funnels 43 these funnels being revoluble with the main shaft 11 and being disposed directly beneath and in vertical alinement withthe pockets l5. A series of can hooks 45 is also secured to the drive shaft l1 below the funnels 43, these hooks being adapted to position and to convey the-successive cans 44 beneath and in vertical alinement with the funnels 43. The main vertical drive shaft I1 is capable of being driven from'a power shaft 46 through a .mechanism for subsequently transporting the cans M to the capping or closing mechanism and to the final cooler, is fullydisclosed inthe said Patent No. 1.857,450,-and need cifically described herein.

During normal operation of the improved sterilizer in order to efiect commercial exploitation of the new process, the granular material which not be spe is to be heat treated, is delivered in bulk to the supply hopper 26 and steam at the proper temperature and pressure is supplied to the interior of the casing II and housing 10 through the pipes 49, 34, thereby maintaining the chamber I3 and the interior of, the casing H under high pressure and temperature, at all times. The main shaft I1 is being rotated tosimultaneously'revolve the can hooks 45, funnels 43, rotor l4 .and members 20, 2|, thus transporting the successive cans 44 and tunnels 43 beneath the discharge opening 36 and also-causing the successive measuring pockets l9 to receive measured batches of granular material from the stationary hopper 26. As the pockets is are filled, they are advanced between the top plate 25 and the closure l2, being automatically sealed from the atmosphere, after which the successive measured batches are deposited in the pockets l5 located therebelow, through the opening 35 in the closure l2. In the pockets I5, the granular mate rial is subjected to high pressure and temperature whereupon the batches are carried over the slots 3'! at which time heating liquid under high pressure and temperature is delivered upwardly through each charge -from the pipe 40. The

pockets l5 substantially filled with mixture .0!

heated liquid and granules, are then advanced until the slots 38 are reached, whereupon the heating liquid will have transferred sufllcient heat units to the granules to insure complete sterilization thereof, and the liquid will be delivered from the pockets l5 through the drain pipe 4!. The batches of heated solids. are next transferred to the slots 39 whereupon previously sterilized liquid is admitted to each pocket I5 and is mixed withthe granular material therein. r

The successive heat treated batches of mixture are subsequently delivered in succession through the opening 38 to the successive cans 44. which are likewise locatedina zone 0! high pressure and temperature, and the cans. are thereafter hermetically sealed and conveyed into a final cooling zone of gradually diminishing temperature and pressure wherein the confined charges are finally cooled. During such cooling of, the batches, the pressure and temperature thereof is' simultaneously reduced to normal. By utilizing liquid at a temperature sufilcient to sterilize the food product and above the normal boiling point and subjected ,to pressure sufiicient to prevent boiling, as a heating medium, the temperature of the liquid may be maintained sufflciently high to insure rapid'and but injects sufilcientheat units therein to insure complete, sterilization of all portions of the product. The initial heating medium may be ordinary water, brine or other liquid, and may or other liquid which has been previously sterl lized and purified, so as to maintain the final batches in natural condition as to appearance and taste. By maintaining the heated granular material under high pressure from the time the same is initially heated until after the cooling liquid has been mixed therewith, danger of degradation is eliminated. and absolutely sterile final batchm are insured. This process is especially applicable to materials which it is desired to finally pack in liquid, and is not intended for use when dry packing is desired- The degree of pressure and temperature maintained within the enclosures, may be regulated to suit the particular commodity being treated, by means. of valves in the pipes 33, 69, and any desired number of these pipes may obviously be provided. If necessary, the pockets l5 may also be, provided with vents for permitting unrestrained ingress of the entering liquid thereto, although such vents may be dispensed with if it is not desired to have the pockets l5 completely filled with mixture. The entire machine when once properly adjusted, operates automatically, and the volumes of the batches of granular material contained in each batch of final mixture, may be quickly varied either while the machine is operating or when it is stopped, thereby permitting packing of various sized cans M, and also permitting variation in theproportions of the mixture. The machine may also be readily assembled and dismantled ior inspection and cleaning, by virtue of the removability of the top closure It should be understood that it is not desired to limit the present invention to the exact details of construction of the machine or to the precise steps or the method, herein shown and descrlbed,'for various modifications within the clent heat units have been transferred to effect, 7 .eomplete sterilization of the solids. and adding sterile cooling liquid to the hot solids.

' 2. The process of sterilizing, which comprises, mixing with granular material a liquid containing sufllclent heat units. to sterilize the granules while the latter are subjected to-high external pressure, removing the liquid after equalization or the temperature of the mixture and while the same is still heated, adding sterile liquid to the heated granular material, and finally hermeti- I cally sealing the mixture. V

3. The process of sterilizing, which comprises,

mixing with granular material a liquid containing sufilcient heat units to sterilize the granules while the latter are subjected to high external pressure, removing the liquid from the granular material after suflicient heat units have been transferred to completely sterilize the granules, and adding sterile cooling liquid to the heated granules while under pressure.

4. The process of sterilizing, which comprises, immersing successive batches of granular matematerial, and hermetically sealing the successive batches of heated. granules.

5. The process of sterilizing, which comprises,

immersing successive batches of granular material in hotrliquid heated to a temperature sumcient to sterilize the granular material and above the normal boiling point of .the liquid and subthe latter, removing the jected to pressure suflicient to prevent boiling of granular material from the liquid while heated, partially cooling the heated material by adding sterile liquid thereto,

hermetically sealing the successive batches of mixture, and allowing the sealed batches to further cool.

6. The process of sterilizing, which comprises, filling the voids of successive batches of granular material with liquid suflicientlv hot to eflect complete sterilization of the granules, removing the liquid from the said voids while the granules are a heatedand subjected to relatively high external pressure, adding other liquid to the heated granules under pressure, and hermetically sealing the I batches of mixture while subjected to said high pressure and thereafter allowing the same to finally cool. v

7. The process of sterilizing, which comprises, rendering a food product sterile by causing the same to contact directly with a liquid-heated to a temperature suflicient to sterilize the product and above itsnormal boiling point and subjected to pressure suflicient to prevent boiling eplace mg the heating liquid with-other .s'terile liquid, and sealing the heat treated mixture of product and other liquid in a container. 1 4

8. .The process of sterilizing, which comprises, rendering a food product sterile by mixing directly therewith a liquid heated to a temperature suf- "ficient to sterilize the product and a pressure suflicient to prevent boiling, replacing the heating liquid with other sterile liquid, and

sealing the sterile mixture in a container.

9, The process of sterilizing, which comprises,

- rendering a food product sterile by mixing therewith a liquid heated to a. temperature 'suiilcient to sterilize the product and subjected to a pressure suflicient to prevent boiling, replacing the heating liquid with other sterile liquid, and sealing the sterile mixture in a container while subjected to high pressure.

10. The process of sterilizing, which comprises,

rendering a food product sterile by mixing therewith a liquid heated above its normal boiling point to a temperature sufficient to sterilize the product and subjected to a pressure sufiicient to prevent boiling, removing heating liquid from the mixture and, replacing the removed liquid with other sterile. materiaLand sealing the final product in a container. 1

11. The process of sterilizing, which comprises,

rendering granular material sterile by mixing it with liquid and subjecting the material to a temperature-sufliciently high to sterilize the same while the mixture is subjected to pressure sufflcient to prevent boiling of the liquid, separating the liquid from the sterile granular material while the latter is maintained under pressure, and add- Y ing sterile cooling material to the sterile removed granular material. A f I 12. The process of sterilizing,=which comprises,

rendering granular material'sterile' by mixing it with liquid and subjecting the material to a temper-attire sufliciently high. to sterilize the same while the mixture is subjected to pressure suffieient to prevent boiling of the liquid, separating the liquid from the sterile granular material while the latter is maintained under pressure, and add- 'ing sterile cooling liquid to the hot sterile gran ular material to produce a sterileflnal mixture.

(DSWALD H. HANSEN. 

